Source code for qiskit_nature.second_q.problems.properties_container

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# (C) Copyright IBM 2022, 2023.
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
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"""Property containment utilities."""

from __future__ import annotations

from import MutableSet
from collections import OrderedDict
from typing import Generator

from import SparseLabelOpsFactory

[docs]class PropertiesContainer(MutableSet): """The properties container class. This class manages storage of :class:`` objects. These objects are operator factories, generating the `aux_operators` that will be passed down to quantum algorithms which support their evaluation. This container class can only contain **a single instance** of any :class:`` kind. It enforces this via a `MutableSet` implementation. """ def __init__(self) -> None: self._properties: OrderedDict[str, SparseLabelOpsFactory] = OrderedDict()
[docs] def add(self, value: SparseLabelOpsFactory) -> None: key = value.__class__.__name__ if key in self._properties.keys(): raise ValueError( f"An object of type '{key}' already exists in this Container. Please remove that " "first, if you want to replace it with this new instance." ) self._properties[key] = value
[docs] def discard(self, value: str | type | SparseLabelOpsFactory) -> None: key: str if isinstance(value, str): key = value elif isinstance(value, type): key = value.__name__ elif isinstance(value, SparseLabelOpsFactory): key = value.__class__.__name__ else: raise TypeError( "Only inputs of type 'str', 'type', or 'SparseLabelOpsFactory' are supported, not " f"{type(value)}." ) self._properties.pop(key, None)
def __contains__(self, key: object) -> bool: actual_key: str if isinstance(key, str): actual_key = key elif isinstance(key, type): actual_key = key.__name__ elif isinstance(key, SparseLabelOpsFactory): actual_key = key.__class__.__name__ else: raise TypeError( "Only inputs of type 'str', 'type', or 'SparseLabelOpsFactory' are supported, not " f"{type(key)}." ) return actual_key in self._properties.keys() def __len__(self) -> int: return len(self._properties) def __iter__(self) -> Generator[SparseLabelOpsFactory, None, None]: for prop in self._properties.values(): yield prop def _getter(self, _type: type) -> SparseLabelOpsFactory | None: """An internal utility method to handle the attribute getter implementation. Args: _type: the target SparseLabelOpsFactory type of this getter. Returns: The property of the corresponding type or `None` if it is not available. """ return self._properties.get(_type.__name__, None) def _setter(self, _property: SparseLabelOpsFactory | None, _type: type) -> None: """An internal utility method to handle the attribute setter implementation. Args: _property: the SparseLabelOpsFactory to set. If `None`, the internally stored property of the indicated type (see next argument) will be discarded instead of set. _type: the target SparseLabelOpsFactory type of this setter. Raises: TypeError: if the provided SparseLabelOpsFactory does not match the indicate type. """ if _property is None: self.discard(_type) return if not isinstance(_property, _type): raise TypeError( f"Only objects of type '{_type.__name__}' are supported, not {type(_property)}." ) self.add(_property)